1. Field of the Invention
The present invention relates to the joining of structural members and, more particularly, relates to an apparatus and associated method for using induction heating to form a localized joint in or between one or more structural members, such as for repairing a structural assembly.
2. Description of Related Art
Localized joints within a single structural member or between portions of multiple structural members are often formed during or after the assembly of such structural members. For example, structural assemblies that are formed by assembling multiple structural members can require localized joining for the repair of one or more of the structural members or the joints between the structural members. According to one conventional method of repairing such structural assemblies in the aerospace industry, a damaged portion of the structural assembly requiring repair is heated and repaired by brazing or otherwise joining a patch of material over the damaged area. A minimum temperature is often required for making an effective repair, and excessive heating can cause damage to the structural assembly or detract from the material properties thereof.
Therefore, a plurality of resistive heaters and thermocouples are fitted to the area of the repair. The resistive heaters are individually energized to provide a distribution of heat to the repair area, and the thermocouples are used to monitor the temperature over the area. Additional energy is provided to the heaters in the cooler areas, and the repair area is thus heated substantially uniformly to a bonding or brazing temperature at which the joint can be formed. Undesirably, the placement of the heaters and thermocouples can be complicated by the geometrical configuration of the structural assembly, the high temperature to which the assembly must be heated, and the need for high uniformity of temperature within the repair region. If the heaters and thermocouples are improperly placed, monitored, or controlled, the assembly can be damaged or the joint can be ineffective. Further, the method is time consuming and labor intensive, lengthening the time and cost of manufacture of the assembly.
Thus, there exists a need for an apparatus and associated method for forming localized joints in and between structural members, including those joined to form complex structural assemblies. The apparatus should provide a uniform temperature to the area of the joint and should also be cost effective and adaptable to variations in the configurations of the structural assembly.